<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
  <head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
    <title>Using Transient Fields in an Entity Binding</title>
    <link rel="stylesheet" href="gettingStarted.css" type="text/css" />
    <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" />
    <link rel="start" href="index.html" title="Berkeley DB Collections Tutorial" />
    <link rel="up" href="SerializableEntity.html" title="Chapter 6.  Using Serializable Entities" />
    <link rel="prev" href="SerializableEntity.html" title="Chapter 6.  Using Serializable Entities" />
    <link rel="next" href="removingredundantvalueclasses.html" title="Removing the Redundant Value Classes" />
  </head>
  <body>
    <div xmlns="" class="navheader">
      <div class="libver">
        <p>Library Version 11.2.5.3</p>
      </div>
      <table width="100%" summary="Navigation header">
        <tr>
          <th colspan="3" align="center">
		Using Transient Fields in an Entity Binding
	</th>
        </tr>
        <tr>
          <td width="20%" align="left"><a accesskey="p" href="SerializableEntity.html">Prev</a> </td>
          <th width="60%" align="center">Chapter 6. 
		Using Serializable Entities
	</th>
          <td width="20%" align="right"> <a accesskey="n" href="removingredundantvalueclasses.html">Next</a></td>
        </tr>
      </table>
      <hr />
    </div>
    <div class="sect1" lang="en" xml:lang="en">
      <div class="titlepage">
        <div>
          <div>
            <h2 class="title" style="clear: both"><a id="transientfieldsinbinding"></a>
		Using Transient Fields in an Entity Binding
	</h2>
          </div>
        </div>
      </div>
      <p>
    The entity bindings from the prior example have been changed in
	this example to use the entity object both as a value object and an
	entity object.
</p>
      <p>
    Before, the <code class="methodname">entryToObject()</code> method combined the
	deserialized value object with the key fields to create a new
	entity object. Now, this method uses the deserialized object
	directly as an entity, and initializes its key using the fields
	read from the key tuple.
</p>
      <p>
    Before, the <code class="methodname">objectToData()</code> method constructed a new value
	object using information in the entity. Now it simply returns the
	entity. Nothing needs to be changed in the entity, since the
	transient key fields won't be serialized.
</p>
      <a id="sentity_partbinding"></a>
      <pre class="programlisting">import com.sleepycat.bind.serial.ClassCatalog;
...
public class SampleViews
{
    ...
    private static class PartBinding extends TupleSerialBinding
    {
        private PartBinding(ClassCatalog classCatalog, Class dataClass)
        {
            super(classCatalog, dataClass);
        }

        public Object entryToObject(TupleInput keyInput, Object dataInput)
        {
            String number = keyInput.readString();
<strong class="userinput"><code>            Part part = (Part) dataInput;
            part.setKey(number);
            return part;</code></strong>
        }

        public void objectToKey(Object object, TupleOutput output)
        {
            Part part = (Part) object;
            output.writeString(part.getNumber());
        }

        public Object objectToData(Object object)
        {
<strong class="userinput"><code>            return object;</code></strong>
        }
    }

    private static class SupplierBinding extends TupleSerialBinding
    {
        private SupplierBinding(ClassCatalog classCatalog, Class dataClass)
        {
            super(classCatalog, dataClass);
        }

        public Object entryToObject(TupleInput keyInput, Object dataInput)
        {
            String number = keyInput.readString();
<strong class="userinput"><code>            Supplier supplier = (Supplier) dataInput;
            supplier.setKey(number);
            return supplier;</code></strong>
        }

        public void objectToKey(Object object, TupleOutput output)
        {
            Supplier supplier = (Supplier) object;
            output.writeString(supplier.getNumber());
        }

        public Object objectToData(Object object)
        {
<strong class="userinput"><code>            return object;</code></strong>
        }
    }

    private static class ShipmentBinding extends TupleSerialBinding
    {
        private ShipmentBinding(ClassCatalog classCatalog, Class dataClass)
        {
            super(classCatalog, dataClass);
        }

        public Object entryToObject(TupleInput keyInput, Object dataInput)
        {
            String partNumber = keyInput.readString();
            String supplierNumber = keyInput.readString();
<strong class="userinput"><code>            Shipment shipment = (Shipment) dataInput;
            shipment.setKey(partNumber, supplierNumber);
            return shipment;</code></strong>
        }

        public void objectToKey(Object object, TupleOutput output)
        {
            Shipment shipment = (Shipment) object;
            output.writeString(shipment.getPartNumber());
            output.writeString(shipment.getSupplierNumber());
        }

        public Object objectToData(Object object)
        {
<strong class="userinput"><code>            return object;</code></strong>
        }
    }
} </pre>
    </div>
    <div class="navfooter">
      <hr />
      <table width="100%" summary="Navigation footer">
        <tr>
          <td width="40%" align="left"><a accesskey="p" href="SerializableEntity.html">Prev</a> </td>
          <td width="20%" align="center">
            <a accesskey="u" href="SerializableEntity.html">Up</a>
          </td>
          <td width="40%" align="right"> <a accesskey="n" href="removingredundantvalueclasses.html">Next</a></td>
        </tr>
        <tr>
          <td width="40%" align="left" valign="top">Chapter 6. 
		Using Serializable Entities
	 </td>
          <td width="20%" align="center">
            <a accesskey="h" href="index.html">Home</a>
          </td>
          <td width="40%" align="right" valign="top"> 
		Removing the Redundant Value Classes
	</td>
        </tr>
      </table>
    </div>
  </body>
</html>
